1) Field of the Invention
The present invention relates to an apparatus for and a method of calculating electromagnetic field intensity in which, when a wave source power is applied, an electromagnetic field intensity can be calculated based on a moment method.
2) Description of the Related Art
Conventionally, an electromagnetic field intensity calculation apparatus that calculates an electromagnetic field intensity around a wave source applied with a wave source power based on a current vector calculated using a mutual immittance matrix of a subject having a wave source and a voltage vector is known. Such an electromagnetic field intensity calculation apparatus applies a moment method to an integral equation derived from Maxwell electromagnetic wave equation to calculate a current of a three-dimensional object with any shape through a numerical analysis.
Specifically, an object is divided into a finite number of small elements, the above-described integral equation is multiplied by a weight function defined within the elements so as to perform integration within the elements so that a matrix regarding mutual immittance matrix about the finite number of elements, and a determinant regarding a voltage vector and a current vector are obtained. A wave source voltage is given so that the determinant is solved so as to meet such a boundary condition that an electric field on a metal surface is zero, thus the current vector of the object is obtained. Further, a radiating electromagnetic field intensity is calculated based on the current of the object obtained in this manner.
For example, Japanese Patent Application Laid-Open No. H07-302278 discloses a conventional art in which a determinant is solved so as to meet such a boundary condition that, when a wave source voltage is applied, an electric field on a metal surface is zero, so that an electromagnetic field intensity is calculated at higher accuracy by calculating not only a current flowing in a printed board but also a common mode current flowing in a cable, a wire, a lead, and a casing.
In recent years, however, when an electromagnetic field intensity of a portable phone or the like is calculated, a wave source power is applied instead of the wave source voltage in many cases. However, the conventional art is a technique constituted to calculate an electromagnetic field intensity by solving the determinant so as to meet such a boundary condition that the electric field on a metal surface is zero, where there is a problem that the electromagnetic field intensity can not be calculated using wave source power.